Clutch control mechanism



T. H. THOMAS CLUTCH CONTROL MECHANISM Aug. 28, 1951 3 Sheets-Sheet 1Filed Aug. 5, 1945' NMY [N VEN TOR. 7779 7456. 720M:

Aug. 28, 1951 T. H. THOMAS CLUTCH CONTROL MECHANISM 3 Sheets-Sheet 2Filed Aug. 3, 1945 INVENTOR.

Aug. 28,1951 I T. H. THOMA$ CLUTCH CONTROL MEcr-mNISM Filed Aug. 5, 1945s Sh ets-Sheet 5 IN V EN TOR.

Patented Aug. 28, 1951 STATES PATENT @FHGE homas Flihqm srs Bend, ignso, B ix Avi tion Corllplfl iiql a FSQWQITFQWL Ind. a corporation .ofDelaware Application August 3, 1945, Serial N '0 608,725

12 Claims. (01.1 %.952)

This invention relates in general to clutch control mechanism and inparticular to a pressure differential operated clutch control mech:anism for operating the friction clutch of an automotive vehicle.

It isan obj eot of my: invention toprovide power means for operating thefriction clutch of an automotive vehicle said power means including apressure difieren-tial operated .motor controlled byan operation oftheaccelerator of the vehicle, the operation of a mechanism, for examplethe electrical generator. ofthe vehicle, operated .by the internalcombustion engine of the vehicle in accordancewith the speed of saidengine and by an operation of a vehicle speed responsive governor andthe gear shift :leverof the vehicle.

When the friction clutch of an automotive vehicle is operated by a powermeans it is of course desirable that said power means simulate asclosely as possible askillful manualoperation of :theclutch. It istherefore. the most important object of my invention to provide aclutchoperat: ing pressure difierential operated motor, the powerelement-of WhiCIL'iS sorcontrolled that in eiiecting the-clutch engagingoperation of said motor the load of the clutch plates is directlyproportional to the R. "P. 'M; .of the internal combustion engine of thevehicle; for .by this operation there :is, underallconditions of clutchoperation, suiilcient force developedaby the engine to drive the drivingplate ofHther clutch.

Yet another object of my invention isto pro-,- vide a two-stage pressuredifferential operated motor for operating the friction clutch of anautomotive vehicle, the-clutch disengaging opera-: tion of said motorbeing in large measure con.- trolled by an operation of a three-wayvalve controlled by an operation of the. accelerator, .a vehicle speedresponsive governorand the transmission controlling shift lever of thevehicle; and the clutch engaging operation of said-motor being in'largemeasure controlledby a balanced type of operation of an air bleed valvemechanism controlledby means comprising the generator of thevehicle orother engine speed responsive mechanism, a differential operateddiaphragm and a governor controlled soecalled vacuum out in valve.

A further objectof myinventionris to provide power means for operatingthe friction clutch of an automotive vehicle said power means.includinga single-acting pressure differential operated motorcontrolled by an accelerator and a gear shift :leverandtgovernorcontrolled three- Way .valve operable "to. ieffecta clutchdisengaging operation of saidomotor and to initiate the first stage of altwo=stage .cl'utch enga ing operation of said motor the :clutchplateecontaotingoper tion, that is the second: stage of ,operationotsaid motor .beingcontrol-led by a bleed valve operableto controlitheflowof air into said rnotor said bleed valvebeing controlled by anengine speed responsive meansoand. by a. pressure ditferentialzoperatedmotor operable in accordance with the degree of gaseous pressure withinthe clutch operating motor. p

A further object of; my. invention is to'provide, a single-actingpressure differential operated motor for moving the drivingmlate ofairiction clutch to its. clutch disengaged position and for controllingthe "operation, of the clutch springs in their operationjof moving saiddriving clutch plate intonengagement. with the driven clutch plate, theclutch engaging. operationof, said motor,

being controlled. in part; by a so;c alled pressure balanced type of:fol1owup valve said; valve being controlled in part .by the generatorof thesvehic-le; or other mechanism the operation .ofwhich is directlyproportional to the speed ofthe engine;

:Yet another object. of my invent o is to pro:- vide a two-stagepressure differential operated motor for operating the friction clutchof an automotive vehiolethefirststage of clutch engag ing operation'lofsaid-motor being efieot by: 31 operation .of the acceleratQrof; thevehicle and; the secondstage of clutch engaging operationot said motorbeing effected-by an; operation of -,a valve controlled byzthegeneratorof theyehicle or any other part of the power plant of thevehicle capable of ,controlling a.:fl0.w ofelectrical current inaccordance with, that is in direct proportion to, the vspeedof theengine of the vehicle.

Yet-another ohieotacftmy invention s to rovide power means. for,operating the friction clutchof: an automotive :vehicle'said power meanstin-l eluding a S ngleaoting pressure; diff rential-open; ated' motorcontrollediby. anpower operated three-.- way valve havin'fillidwtransmittin onnections with .=the atmosphere, a- -souro.e-offlvacuum, and the motor, the conneotionwithwthevatmospherfibeing controlled by; a power operated threeevvay valve operable to\control the: gaseous pressure within the motorin? its; operation; ofcontrollin the, engagement. of the clutch.

.Otherobiectsrof the; invention; will; appear, moreqfully hereinafterrom theifo11owine-detai1ed d r ptiontwhenrtakenz in:.-conn.ectionviwi-th the accomp nyingldraivin wherein a; sin ombodi e mentof theinventioniss fllustrated; I

atcaooi Figure 1 is a diagrammatic view disclosing the principalfeatures of my invention;

Figure 2 is a plan view looking down upon the top of the air bleed valvemechanism of my invention;

Figure 3 is a longitudinal sectional view of the air bleed valve takenon the line 3-3 of Figure 2;

Figure 4 is a sectional view, taken on the line 44 of Figure 3disclosing the details of the valve operating motor and details of thesolenoid oper-.

ated vacuum cut-in valve built into the so-called air bleed valvemechanism; and

Figure 5 is a sectional view disclosing details of the so-calledthree-way transfer valve of the clutch control mechanism constituting myinvention.

Describing now that embodiment of my invention disclosed in the severalfigures of the drawings the principal elements thereof consist of asingle acting vacuum motor l comprising a casing l2 and a power elementsuch as a piston, not shown, which is connected to a friction clutch,not shown, of a conventional design, that is, one including driving anddriven elements. One end of the casing of the motor, a portion of thebody thereof and the power element together outline a control chamber,the gaseous pressure within said chamber being controlled to control theoperation of the motor. The force transmitting means interconnecting thepower element of the motor with the clutch preferably includes afiexible cable l4 connected to a crank l6 and said crank is fixedlyconnected to a shaft 18 which is connected to the clutch. A footoperated pedal 20, contactable with a flange 2i extending from the crankI6, is also preferably included in the clutch operating mechanism.

One end of the motor In, that is, the end of the same constituting apart of the aforementioned power compartment of the motor, is connectedby a conduit 22 to a compartment 24 of a power operated three-way valveunit indicated as a whole by the reference numeral 26 and disclosed indetail in Figure 5. A compartment ll of said three-way valve unit 26 isconnected, by a conduit l3, with a compartment 25 of a power operatedair bleed control valve l; and the aforementioned compartment 24 isconnected, by a conduit I], with a conduit l9 which conduitinterconnects the air bleed valves I5 with a vacuum tank 9 said tankbeing connected, by a conduit 1, with the intake manifold of theinternal combustion engine. The intake manifold is indicated by thereference numeral H2 and the engine by the reference numeral H4.

Describing now the details of the power operated air bleed valve thecasing of said valve is provided with a cylindrically shaped bore toreceive a cylindrical sleeve valve member 28 constituting one of the twoparts of a three-way valve; and said casingis counter-bored to providethe aforementioned compartment 25, Figure 3. A spool shaped valve member30, provided with a cylindrically shaped bore to permit the passage ofair therethrough, constitutes the other part of the three-way valve. Oneend of the latter valve member is provided with opposed slots to receivetherebetween a floating lever member 32 which lever member is pivotallyconnected to the valve member by a pin 33 extending through said leverand mounted in openings in the end of said valve member. The smalldiametered portion of a spool shaped end portion of the valve member 30registers at all times with a vacuum port 34 in the sleeve 28 said portregistering with a diagonally extending duct 36 within the valve casingsaid duct leading to a valve compartment 40, Figure 4. The sleeve 28 is,as disclosed in Figure 3, provided with transversely extending ports 42and 43 which are at times, that is when the three-way valve is lapped,covered by a land 44 constituting the peripheral portion of the endflange of the spool shaped valve member 30, The valve 30 is shown in itslapped position in Figure 3.

A pin 46 is reciprocably mounted at one of its ends within a recess 48in the valve casing and is detachably connected at its other end to aspring,

- pressure differential and electromagnetically operated diaphragm 50which is detachably secured at its periphery, by bolts 52, to a flangeportion 53 of the valve casing and to a cup shaped casing member 54. Thelatter member houses one of the most important elements of my invention,that is, an electromagnet comprising a winding 5| and an armature 55;and said armature is secured to the central portion of the diaphragm 50.p

The winding 5| is preferably wired to a source of electrical current,for example, the generator of the vehicle, whereby the degree ofenergization of the electromagnet, that is the degree of current flowingthrough the winding 5|, is directly proportional to the R. P. M. of theinternal combustion engine of the vehicle. It is to be particularlynoted that the current flow through the electromagnet 51, 55 need notnecessarily be controlled by the generator; for it is within the purviewof my invention to employ any engine driven mechanism as a means forcontrolling the current to the electromagnet it being necessary howeverthat the degree of said current be directly proportional to the speed ofthe engine.

The casing member 54,. the flange portion 53, a spacer ring 56, theend'portion of the valve casing, the electromagnet and the diaphragm 50together constitute a motor 59 constitute a part of the means foractuating the reciprocable threeway valve member 30. A spring 58, thefriction of which is described hereinafter, is interposed between oneend face of the armature 55 and a spring retainer cup member 62 thecentral portion of which is contacted by the end portion of a pin 64adjustably mounted ina'boss 51 projecting from the end of the casingmember 54. The spring 58 is housed within what is termed the controlcompartment 68 of the motor 59 and the remaining compartment 10 of saidmotor is at all times vented to the atmosphere via a port 12.

To this port there is connected a conduit 14, Figures l and 2,preferably leading to an air cleaner 15. The degree of compression ofthe spring 58 may be varied by varying the position of the pin 64 withinthe boss 51.

To the upper end of the lever 32 there is pivotally connected the innerend of a pin 15 adjustablymounted, by means of a set screw '11,

within a portion of the valve casing bored to receive said pin.

Completing the description of the bleed valve unit l5 the casing isprovided with ducts 92 and 93, Figure 3, permanently interconnecting thecontrol compartment 88 of the motor 59 with the aforementioned valvecompartment 25. There is thus provided fluid transmitting means for atall times interconnecting the compartment 68, the valve compartment 25and the control compartment of the clutchoperating motor Hi. It is to benoted at this juncture that the clutch 5 control mechanism constitutingmy invention is in large measure controlled by controlling the gaseouspressure within the valve comp'art ment 25.

Referring now to Figure 4 there is here disclosed the details of asolenoid and spring operated vacuum cut-in three-way valve unit saidunit cooperating with the three-way bleed valve 30 to effect the desiredtwo stage clutch engaging operation of the motor I0. To a portion of thevalve casing there is secured, by set screws 94, Figure 2, a cap member95 constituting a part of a solenoid indicated as a whole by thereference numeral 96. This solenoid comprises a winding 93 and anarmature I00 the latter having secured to its reduced inner end a vacuumcut-in valve member I02 housed within the aforementioned compartment 40.When the solenoid -96 is energized the armature I00 is drawn downwardly,Figure 4, against the resistance of a compression spring I04. With thisoperation the valve member I02 is seated at I06 thereby interconnectingthe chamber 46 with a port I 08 which port, by virtue of the conduit I9,is connected with a vacuum tank 9 which is in turn connected with theintake manifold II2 of the internal combustion engine II4 of thevehicle. As is well known in this art the intake manifold of the enginebecomes a source of vacuum when the throttle of the engine is closed. Acheck valve H1 is preferably interposed in the connection between theintake manifold and the tank 9. A duct I09 in one of the parts of thecasing of the valve operating motor 59 provides a means for venting thecompartment 40 to the atmosphere when the valve member I02 is moved offof its seat by the spring I04; for it will be remembered that thecompartment 10, to which the duct I09 is connected, is vented to theatmosphere by the port 12, Figure 3. There is thus provided a compactbleed valve control unit for controlling the engagement of the clutchsaid unit comprising a multi-sectioned casing housing two three-waycontrol valves and also housing means for oper, ating said valves.

Completing the description of the clutch control mechanism constitutingmy invention the accelerator H3 of the vehicle is connected to athrottle operating crank I20 by the several links and bell crank leversdisclosed in Figure 1; and as will appear from the description to followone feature of my invention lies in a lost motion connection I22 in theconnection between a bell crank lever I24 and the accelerator.

Describing now the electrical control means of my invention, as isdisclosed in Figure 1 the valve operating solenoid 95 is controlled bygrounded selector lever operated breaker switches I 48-and I50.electrically connected in parallel with each other, and by a groundedvehicle speed respone sive governor operated breaker switch I52 which iselectrically connected in parallel with the aforementioned switches I48and I50; and the armature of a solenoid I2.-I, operative to actuate avalve member 123 of the three-way valvez26, is controlled by theaforementioned switches 148, I50 and I52 and by an accelerator operatedbreaker switch I21. As is disclosed in Figure 1 the latter switch iselectrically connected in series with the solenoid I21 and theaforementioned grounded switches I48, I50, .and I52 the latter threeswitches being connected in parallel with each other. The constructionof the breaker switch I21 and its connection with the acceleraetor issuch that the same is closed when the ac- "celerator iscompletely-released and is'opened prior to takingup the lostmotion ofthe lost mo-' tion connection I22; A transmission and clutch operatingselector lever I54 is preferably connected with the switches I48, I50and transmission operating cranks I55 and I58, by the force transmittinglinks and levers disclosed in Fisure 1.

Describing the operation of this force. transmitting means and theconstruction thereof, a spring I60, interposed between a stop I62fixedly secured to the steering post I64 of the vehicle and astop I66fixedly secured to a shaft I68, serves to bias said shaft downwardly tothe position disclosed in Figure 1. To the lower end of the shaft I68there is fixedly secured a crank I16 through which extends a pin I12;and when said shaft is moved downwardly by the spring I60 one end ofsaid pin moves into a slot I14 in a floating crank I16. To one end ofthe crank I16 there is pivotally connected a rod I18 said rod beingpivotally connected at its other end'to theend of the crank I58. Thiscrank when 110- tated clockwise serves to actuate other forcetransmitting meanswithin the casing of a three speeds forward andreverse transmission I to establish the transmission in its high gearsetting; when the crank I16 is rotated counterclockwise saidtransmission is established in its second gear setting.

The crank I56 whenrotated clockwise serves to establish the transmissionin its low gear set: ting and when rotated counterclockwise serves toestablish the transmission in reverse gear. The connection between thecrank I56 .and' the shift lever I54 includes a link 1'82 pivotallyconnected to a floating lever I84 said lever being slidably androtatably mounted on the shaft I68. This lever I84 is provided with aslot I66 to re: ceive one end of the pin I12.

When the driver wishes to establish the transmission in its second gearsetting he rotates the shift lever I54 counterclockwise and this operastio n serves to rotate the floating lever I16. Now the switch I48 ispreferably so constructed that the force necessary to close the same,that is the force necessary to compress a spring within the switchconnected to its movable contact, is less than the force necessary toeffect the initial movement of the high, second shift rail of thetransmission I80. It follows therefore that the initial movement of theshift lever results in a pivoting of the lever I16 about its connectionwith the link I18; and this operation results in a closing of the clutchcontrolling switch I48. Continued movement of the shift lever, that isthe movement after the switch I48 is closed and there is no possiblefurther movement of a link I88 interconnecting the lever I16 with saidswitch, results in a clockwise rotation of said lever about its pivotalconnection with the link I88; and this operation results in acounterclock-- wise rotation of the crank I58 to establish thetransmission in its second gear setting. After this setting isestablished the driver removes his hand from the shift lever whereuponthe afore-. mentioned spring within the switch I48 operates to rotatethe lever I16 clockwise about its piV-- oted connection with the link I18 to thereby open said switch. This switch is so constructed that thesame is also closed when the drivermoves the shift lever to establishthe transmission in its high gear setting; and the spring means withinsaid switch also functions to open the, same when the hi h ear setting:ofthe trans? mission has been established and the driver re,- moves hishand from the shift lever. V In this high gear: operationof themechanism the operation of thelever I16 is in part the reverse of itsoperation in effecting a second gear setting of the transmission; .forwhen the shift lever I54 is rotated in a clockwise direction toestablish the transmission in high gear the lever I'IS is first rotatedcounterclockwise about the pivotal connection between the rod I18 andthe lever I16 to close the switch I48; and the lever I10 is then rotatedin acounterclockwise direction about its pivotal connectionwith the linkI88 to effect the aforementioned high gear setting of the transmission.:7 ZDescribing the operation of the switch mecha; nism to establish thetransmission in either reverse gear orlowgearthe driver first rotatesthe shift lever upwardly in a plane perpendicular to the;plane of thesteering wheel; and this operation serves to bodily move the shaft I68upwardly against the tension of the spring I00. The upper end of the pinI12 is by this operation moved into the slot I86; and a subsequentrotation of the shiftlever, either .to establish the transmission inreverse or low gear, results in a rotation of the cranks I10 and I50 andthe lever I04 to effect one or the other of these settings of thetransmission. The shaft IE8 is provided with an hour-glass shaped recessportion I90 which receives a pin I92 operably connected to the groundedbreaker switch I50; and as will be obvious from an inspection of Figure1 when said shaft is moved upwardly, in the operation of establishingthe transmission in either reverse or low gear, the switch I50 is closedby virtue of the forcing of the pin I92 to the left, Figure 1, when theend of said pin is forced onto a cone shaped portion of the recess I90;then after the low gear or reverse gear operation of the transmission iscompleted the driver will release the shift lever whereupon the springwithin the switch I50 will open said switch the shaft I68 being bodilymoved as the pin I92 returns to the center of the recess I90. In thelatter operation the pin II2 moves out of the slot I86. When the gearshift lever is operated to shift the transmission from either itsreverse gear setting or its low gear setting to either its second gearsetting or high gear setting, the first increment of movement thereofresults in a closing of the switch I50 as the pin H2 is moved back intothe slot I06. The power means is then again rendered operative todisengage the clutch to facilitate a neutralization of the transmission.The shift lever is then moved to its transmission neutral positionpreparatory to a movement thereof to establish the transmission ineither its high or second gear setting; and this transmissionneutralizing movement of the shift lever effected by the expansion ofthe spring I60, serves to open the switch I50. Thereafter the shiftlever is moved to establish the transmission in either high or secondgear the switch I 48 being operated to effect an operation of theclutch, all as is described above.

There is thus provided, by the above described shift lever operatedswitch operating mechanism, means for effecting a clutch disengagingoperation of the motor I during the first increment of movement of theshift lever as it is moved to establish the transmission in any one ofits four gear settings. To effect this operation however it is of coursenecessary to first release the accelerator to close the switch I21. The

parts 'of, the mechanism are preferably so constructed and arranged andso operative that the clutch is disengaged before thetransmission isoperated. It is also to be noted that the switch operating forcetransmitting means of my invention is such as to effect a closing of theclutch control switch mechanism when the shift lever is moved in eitherone of two different planes said switch mechanism being .automaticallyopened by a release of the shift lever said operation serving to effecta re-engagement of the clutch. Briefly describing the clutch disengagingoperation when the switch I21 and any one of the switches I48, I50 andI52 is closed then the ground connection to the solenoid I2I iscompleted and the so-called hot wire connection from said solenoidcouples the latter with a grounded battery 202; accordingly the solenoidI2I is energized and with this operation the valve I23 is operated toconnect the control compartment of the motor I0 with the intake manifoldtherebyenergizing said motor to effect a disengagement of the clutch.Referring to the aforementioned hot wire connection there is includedtherein a cut out switch 203 and the ignition switch 205 of the vehicle.

The above described clutch control mechanism of my invention may beincorporated in the power plant of a vehicle which includes a so-calledkickdown type of selective gear transmission that is a transmissionwhich may, by a manual operation of a'shift lever, be established in oneor the other of two forward gear settings and a reverse gear setting;and after one of said forward gear settings is established then a vacuumand spring operated kickdown motor unit, controlled by a vehicle speedresponsive governor and the accelerator of the vehicle, takes over theoperation of said transmission. In this type of well known transmissionmechanism the kickdown or downshift operation of the motor unit isfacilitated by a momentary disabling of the ignition system of theengine; and the power plant including such a mechanism may also includea fluid coupling.

Describing now the complete operation of the mechanism constituting myinvention and incidentally completing the description of the partsthereof not heretofore described, when the accelerator' I I8 is releasedto close the throttle and idle the internal combustion engine H4, theiii-'- take manifold II2 of said engine is partially evacuated to inturn evacuate the tank 8. There is thus provided a source of vacuum forenergizing the motor I0 to disengage the friction clutch of the motorvehicle; and as described above this operation is effected with therelease of the accelerator and either an operation of the shift leverI54 or a slowing down of the vehicle below governor speed either of saidoperations effecting an energization of the solenoid I2I to open thevalve I23. Incidentally the parts of the mechanism are so constructedand arranged that the valve member 30 and the means for operatingthesame assume, at this time, the relative positions disclosed in Figure 3.Explaining the latter operations when the valve I23 is opened as aresult of the energization of the solenoid I2I the motor I0 is energizedto disengage the clutch; and at the same time the solenoid 96 isenergized to open the valve I02 thereby connecting the port 34 of thevalve I5 with the source of vacuum. The latter operation results in anenergization of the motor 59 to move the valve member 30 to its lappedposition,

aces-p01 thatv is, the position disclosed in :Figure :3. The several.forcesacting-upon the valve member 30 to eifect this lappingoperationare described in detail hereinafter.

.To initiate the clutch r engaging *operation .of the powermeans-of-myinvention, that is,-efiect the so-called firststageofclutch-engaging operation of the motor I0, the driver, if the clutch hasbeen disengaged incident to an operation of the transmission.testablishthetsame either in its second gear'setting or "its high gear setting,releases his. grip-uponthe shift lever [54 to -.permit the springwithinthe: switch I M8-to open-said switch; or hemay initiate theclutch-engaging operation by 'depressingrthe accelerator to open theswitch I21; andeither one -0ffthese (operations eifects a'deenergizationof the, solenoid I2 I thereby permittingzaspring -206-to close the valvemember I23, that is connect the control compartment of:the motor[Dz-with the compartment 25 ofthe bleed valve .15- via:the conduits -22=and I3. Airis then drawn out of the compartment 68 of the valveoperating motor :59 into the-control compartment ofthemotor II] by theclutchenaging, that is :expanding operation, of the clutch springs; :andthis :operation, resulting in the creation of;azpartial'zvacuum'inthecompartment 68, servesto draw the'valve member'3flto the left, Figure 3,.to'vent the :ports 42 and-ll3 to the atmosphere 'via a valvecompartment 2 I 0, the interior of'thevalvemembertfland the atmosphericvent .port 12. iExplaining in greater detail this operationofzmovingthevalve member 30 to the'left'it will:be:apparent, .from aniinspection ofFigure3, that when the-compartment 68 is partially evacuatedrthei'diaphragm :50 :is subjected to a-differential of pressures;for-the motor compartment 10 is at :'the time "vented-to the atmospherevia thei'port :12. :Air'rthen rushes into the oompartment fi8andthe-control compartment of themotor lflyand when-thegaseous pressurewithin said compartments reaches ,a certain factor, that is the' factorto effect :a lapping of the valve member "30, then said -'valve member30 is again lapped.

Now as to this valve-lapping operationa very important feature of myinvention lies in the construction, arrangement and adjustment ':of theparts of the valve l5, including-a setting of the pin 16, the'strengthof thespring58, andthe motor idling pull of theelectromagnet l,"-55, toautomaticallyeffect a lapping'of the valve"'30 when the gaseous pressurewithin the motor in reaches .a certain factor; and'it is to beremembered that the'gaseous pressure-within the compartment 63 and'thecontrol compartment-ofthe motor H). is the same atall times. The partsofthe mechanism :are preferably so constructed and arranged and sooperative "that the first stage of .the clutch engaging operationthat ismovementof the driving clutch :plate, is terminatedjust. prior to-thecontacting of the clutch plates;.and.the valve 30 is automaticallylapped whentthisoccurs.

Now. toeifect the ,all important controlled enagement .oftheclutchplates, that is, to efiect thersecondstage operation of thepower means of my invention, thedriver continues the depression.oftheaccelerator therebyefiecting anopening of the throttle to speed-upthe engine; and thisoperation resultsin-an increase in the pull of theelectromagnet. 51,55 with-a resultant leftward. movement-lofthe valvemember 3 0 ,to again vent the motori0 :and the valve :compartment 68 tothe-atmosphere. "This ,resultslin a reduction of the differential of,vpressures .acting upon the power element .of the :motor vIllw-itharesultant certain loading .of .the .clutch plates. Then when thegaseous. pressure within .the compartment 68 is increased sufiicientlyto makelthe leftward pullof the diaphragm plus the. leftward pull of=the .electromagnet equal to the rightward push of -.the springl58 thenthe valve 30 isagainlapped. Themotor59 including .the diaphragm .50, thespring .58 and {the electromagnet 5l, constitutesactuatorsserving ,tooperate-the valve member .30.

It is apparent therefore that there .is ,provided, by the bleedcontrelvalve .1 5.,of .my .invention, .means for effecting a clutch plateloading which is directly proportional to the. speed of the engine; and.thisisexactly the-result desired for the engine :torque necessary .to:drive ,the driving clutch .plate should -.increase.,pr.oportion atelywith the .increasetin clutch ,plateloading'. It is to be notedthatwiththe-,mechanismlof my invention .the .summationof theloads .of thediaphragm 5ll..and .the electromagnet 5|, 55 always equals the.constantforce exerted by the spring .58 ,to .efiect aflapping of the valve"30.As the load of the electromagnet increases rthedoa'd of the diaphragm50decreases; for with.v an increase in the former load the valve 30 'ispulled to the left, Figure 3, .to vent the compartment 68 to theatmosphere;. and when this occurs the differential .of pressures actingon the diaphragm 50 is lowered. It follows therefore .that when thedriver'wishes to increase the clutch plate loading said operationmay'beeffected merely y depr ssin the accelerator .to increase the speed ofthe engine; forthis operation resultsin the proportionately ggreaterenergization of the electromagnetand this results ina'reduced'energization of the motor I 0.

An importantfeature of "my invention lies'in the operation of thegovernor controlled vacuum cut-in valve l1l2; for1it is'to be noted thatafter the valve 30 .is lappedshould the speed of the engine .then bereducedine. if theengine labors, then the three. forces maintaining saidvalve lapped will. be unbalanced thereby resulting in a. movementof thesameto the ri ht, Figure 3, to uncover the ports .42 and Hand reconnectthe motor In with thesource of vacuum, that is the tank ,9. Thepresenceof said tank insures a source of vacuum at all .timesduringthe.operation ,of the clutch.control ,mechanism .of inyinvention. Thisoperation will, of course, through the .increasein energizationlof themotor 1!], result flinaylessening of the then existing clutchplate,load,thatis, the'load causingthe en ine to labor.

Now the vacuumconnectiontothe valve port 34,..Figure.,3,.is controlledby the vacuumcut-in valve I02 the operation of which, .by virtue of theelectrical controlmeans disclosed inFigure'l, is .controlled in part,by'the vehicle. speed responsivegovernor, motshown. Below governorspeed the governor operated switch IE2 is closedto energize the solenoid.56 to .openthe valve [02 accordin ly .it..f011ows that :the ,abovedescribed what may be termed .recovery operation of ,theclutchc0ntr01.mechanism..is ,only possible when the vehicle .istravelling below the s,o-..ca11ed governor :speed; but with ,normaldriving .the engine torque .is relativelyhigh ,whenthe vehicleistravellingata fairly .high speed that 'isabove the ,sowalled ,governorspeed accordingly "the above described recovery of the mechanism is notneeded at this time. 7

There is thus provided a simple, compact and automatic clutch controlmechanism the clutch being automatically disengaged when the acceleratoris released and either the speed of the 'car is reduced below a certainfactor to operate the governor operated switch 152 or the driveractuates the selector lever I54 to operate the transmission therebyoperating one or the other of the switch 148 and I50. The clutch issubsequently reengaged in two stages when the car is traveling at orbelow a certain speed, the first of the two stages of operation beinginitiated by a depression of the accelerator to open the switch I21 tothereby effect a closing of the valve I23, and the second of the twostages of operation being effected by depressing the accelerator to openthe throttle, the clutch plate loading during said engagement beingdirectly proportional to the engine speed; and the clutch is engaged intwo stages when the car is traveling above the aforementioned certainspeed, that is, governor speed, the first stage being initiated by anopening of either of the switches (48 or I50 and the second stage beingefiected by an opening of the accelerator as discussed above.

I claim:

1. In an automotive vehicle provided with a friction clutch, an internalcombustion. engine, a gear shift lever, a vehicle speed responsivegovernor, an accelerator, an engine throttle, and means, including alost motion connection, interconnecting the accelerator and throttle;power means for operating said clutch to effect a disengagement of theclutch and a two-stage engagement thereof, said power means comprising apressure difierential operated motor the power element of which isoperably connected to the clutch, and valve means for controlling theoperation of said motor including a three-way valve operable to effect aclutch disengaging operation of said motor and to initiate the clutchengaging operation thereof, a solenoid and a spring for controlling theoperation of said threeway valve, electrical means, including anaccelerator operated switch operable during the lost motion operation ofthe aforementioned accelerator to throttle connection, for controllingthe operation of said solenoid, said motor controlling valve meansfurther including a bleed valve operable to control the flow of air intothe motor and thereby control the clutch engaging operation of saidmotor, and means for controlling the operation of said bleed valvecomprising a pressure differential operated motor and an electromagnetoperable in accordance with the speed of the engine.

2. In an automobile vehicle provided with a change speed transmission,an internal combustion engine having a throttle valve and a frictionclutch; power means for operating the clutch comprising a pressuredifferentialoper ated motor operably connected with the clutch, valvemeans for controlling the operation of the motor including a three-wayvalve operable to effect a clutch disengaging operation of the motor andto initiate a clutch engaging operation thereof, means for controllingthe operation of said three-way valve including a switch operableincident to the operation of the throttle and a switch operable incidentto the operation of the transmission, said three-way valve controllingmeans serving to open said valve to efiect a 12 clutch disengagingoperation of the motor when the throttle is closed and when thetransmission is being operated; said motor controlling valve meansfurther including a three-way bleed valve mechanism for controlling thedecrease in dif ferential of pressures acting on the power element ofthe motor to thereby control the clutch engaging operation of the motor,said bleed valve mechanism including a follow-up valve, the operation ofwhich is controlled in accordance with the speed of the engine and thedegree of gaseous pressure within the control compartment of thepressure difierential operated motor.

3. In an automotive vehicle provided with an internal combustion engineincluding an intake manifold, a throttle, an accelerator, forcetransmitting means, including a lost motion connection, interconnectingthe throttle and accelera tor, a vehicle speed responsive governor and afriction clutch; two-stage power means for operating said clutchcomprising a pressure differential operated motor operably connected tothe clutch, valve means for controlling the operation of said motorincluding a three-way valve operative to effect a clutch disengagingoperation of the motor and to initiate a clutch engaging operationthereof, a bleed valve mechanism for bleeding air into the motor tocontrol the clutch engaging operation thereof, air transmitting meansinterconnecting the intake manifold with the latter valve mechanism andwith the threeway valve, air transmitting means interconnecting thebleed valve mechanism with the threeway valve, air transmitting meansinterconnecting the three-way valve with the motor, means forcontrolling the operation of the three-way valve comprising a switchoperated by the governor and a switch closed when the accelerator isfully released and opened during the taking up of the lost motion in theconnection between the accelerator and throttle, means for operating thebleed valve mechanism including electromagnetic means operative inaccordance with the speed of the engine and further including pressuredifierential operated means operative in accordance with the gaseouspressure existing within the aforementioned clutch operating motor; theparts of the clutch control mechanism being so constructed and arrangedand so operative that the clutch is disengaged when the accelerator isfully released and also so operative that the first stage of engagementof the clutch is completed just prior to an opening'of the throttle andthe second stage of engagement of the clutch is initiated when the speedof the engine is increased above idling speed.

4. A clutch control mechanism comprising a single-acting pressuredifferential operated motor adapted to be connected to a clutch and acontrol mechanism for said motor comprising a power operated three-wayvalve, a power operated three: way bleed valve operable to control theflow of air into the motor and at times from the motor via the three-wayvalve, fluid transmitting means adapted to connect the power operatedthree-way valve with a source of vacuum, fluid transmitting meansconnecting the power operated three-wayvalve with the motor and fluidtransmitting means interconnecting the power operated three-way valvewith the power operated three-way bleed valve. 7

5. A clutch control mechanism comprising a pressure differentialoperated motor adapted to be connected to a clutch and a controlmechanism for said motor comprising a power operated reater three-wayvalve, a three-way bleed valve operable to control the air into themotor and at times from the motor via the three-way valve, fluidtransmitting means adapted to connect the power operated three-way valvewith a source of vacuum, fluid transmitting means connecting the poweroperated three-way valve with the motor, fluid transmitting meansinterconnecting the power operated three-way valve with the three-waybleed valve, and power means for operating the latter valve including apressure difierential operated motor.

6. A clutch control mechanism comprising a pressure differentialoperated motor adapted to be connected to a clutch, and a controlmechanism for said motor comprising a power operated three-way valve, athree-way pressure balanced bleed valve operable to control the flow ofair into the motor and at times from the motor via the three-way valve,fluid transmitting means adapted to connect the power operated three-wayvalve with a source of vacuum, fluid transmitting means connecting thepower operated three-way valve with the motor, fluid transmitting meansinterconnecting the power operated three-way valve with the three-waybleed valve and power means for operating and controlling the operationof the latter valve including a pressure differential operated motoroperable, together with other means, to move the valve to any one ofplurality of control positions, and a solenoid operated vacuum cut-invalve operable, at times, to connect the bleed valve with a source ofvacuum.

7. A clutch control mechanism comprising a pressure differentialoperated motor adapted to be connected to a clutch, and a controlmechanism for said motor comprising a three-way valve operable to effecta clutch disengaging operation of the motor and initiate a clutchengaging operation of said motor, a pressure balanced three-way bleedvalve movable to a plurality of control positions including a lappedposition said valve being operable to control the power fluid flowinginto the motor and at times from the motor to control the clutchengaging operation of said motor, fluid transmitting means adapted toconnect the three-way valve with a source of vacuum, fluid transmittingmeans connecting the three-way valve with the motor fluid transmittingmeans connecting the three-way valve with the three-way bleed valve, andpower means for operating and controlling the operation of the lattervalve including a pressure differential operated motor, a spring, and anelectromagnet the valve operating load exerted by two of the latterthree mechanisms varying the clutch engaging operation of the clutchcontrol mechanism, the summation of said loads being a constant when thevalve is lapped.

8. In an automotive vehicle provided with a change speed transmissionand a friction clutch, power means for operating the clutch including apressure difierential operated motor operably connected to the clutch,valve means for controlling the operation of the motor including athreeway valve operable to efiect an energization of the motor todisengage the clutch and also operable to initiate an engagement of theclutch by efiecting a de-energization of the motor, a pressure balancedthree-way bleed valve operable to control the flow of power fluid intothe motor and, at times, from the motor via the three-way valve tothereby control the clutch engaging operation of the motor, means forcontrolling the operation of thebleed valve including a vacuum cut-invalve operative to control the connection" between the bleed valve and asource of vacuum, means for controlling the operation of the vacu-' umcut-in valve including electrical means operative to open the valve whenthe vehicle is traveling below a certain speed, and means, in cluding apressure differential operated motor, for actuating the bleed valve.

9. A clutch control mechanism comprising a single-acting pressuredifferential operated motor adapted to be connected to a clutch and acontrol mechanism for said motor comprising a threeway valve, athree-way bleed valve operable to control the flow of air into the motorand at times from the motor via the three-way valve, fluid transmittingmeans adapted to connect the three-way valve with a source of vacuum,fluid transmitting means connecting the three-way valve with the motorand fluid transmitting means interconnecting the three-way valve withthe three-way bleed valve.

10. A clutch control mechanism comprising a pressure differentialoperated motor adapted to be connnected to a clutch and a controlmechanism for said motor comprising a three-way valve, a three-way bleedvalve operable to control the flow of air into the motor and at timesfrom the motor, fluid transmitting means adapted to connect thethree-way valve with a source of vacuum, fluid transmitting meansconnecting the three-way valve with the motor, fluid transmitting meansinterconnecting the three-way valve with the three-way bleed valve, andpower means for operating the latter valve including a plurality ofmotors comprising a pressre differential operated motor.

11. A clutch control mechanism comprising a pressure differentialoperated motor adapted to be connected to a clutch, and a controlmechanism for said motor comprising a three-way valve, a three-waypressure balanced bleed valve operable to control the flow of air intothe motor and at times from the motor, fluid transmitting means adaptedto connect the three-way valve with a source of vacuum, fluidtransmitting means connecting the three-way valve with the motor, fluidtransmitting means interconecting the three-way valve with the three-waybleed valve, and power means for operating and controlling the operationof the latter valve includ- -ing a pressure diflerential operated motoroperable, together with other means, to move the valve to any one ofplurality of control positions, and further including a solenoidoperated vacuum cut-in valve operable, at times, to connect the bleedvalve with a source of vacuum.

12. A clutch control mechanism comprising a fluid pressure operatedmotor adapted to be connected to the friction clutch of an automotivevehicle and a control mechanism for said motor comprising a three-wayvalve operable to effect a clutch disengaging operation of the motor andto initiate a clutch engaging operation of said motor, a three-way bleedvalve operable to control the power fluid flowing to the motor and attimes from the motor to control the clutch en- 2,566,001 15 i6 three-waybleed valve said two power means in- REFERENCES CITED eluding a manuallyoperable switch mechanism The f 110 m at r s f d 1 adapted to beactuated by a transmission operatfile of Q a i e ence are 0 recur n theing gear shift lever and operable to control the operation of both thethree-way valve and the 5 UNITED STATES PATENTS three-way bleed valve,and further including a Number Name Date switch mechanism adapted to beactuated by a 2,348,435 Hey et a1 May 9, 1944 vehicle speed responsivegovernor and operable 2,365,469 Hey et al Dec. 19, 1944 to control theoperation of both the three-way valve and the three-way bleed valve. 10

THOMAS H. THOMAS.

